Changes in white matter microstructure and brain tissue
volume during late childhood and early adolescence were studied using
voxel-based analysis of diffusion parameters and deformation-based volumetric
measures, utilizing a non-linear registration algorithm. Fifteen healthy
children were examined longitudinally, at baseline and a 15 month follow-up.
Statistical analyses revealed significant ADC decrease and FA increase, and
axial and radial diffusivity decline in several regions (internal and external
capsule, forceps minor, and corona radiata). A trend to increased tissue volume
was also detected in several regions. These results suggest continuation of
regional brain maturation and increase in fiber density during late childhood.